Recombinant Mouse Mucin-4 (Muc4), partial

Function

Membrane-bound mucin, a family of highly glycosylated proteins that constitute the major component of the mucus, the slimy and viscous secretion covering epithelial surfaces. These glycoproteins play important roles in the protection of the epithelium and are implicated in epithelial renewal and differentiation. Regulates cellular behavior through both anti-adhesive effects on cell-cell and cell-extracellular matrix interactions and its ability to act as an intramembrane ligand for ERBB2. Plays an important role in proliferation and differentiation of epithelial cells by inducing specific phosphorylation of ERBB2. In polarized epithelial cells, segregates ERBB2 and other ERBB receptors and prevents ERBB2 from acting as a coreceptor. The interaction with ERBB2 leads to enhanced expression of CDKN1B. The formation of a MUC4-ERBB2-ERBB3-NRG1 complex leads to down-regulation of CDKN1B, resulting in repression of apoptosis and stimulation of proliferation. Its ability to promote tumor growth may be mainly due to repression of apoptosis as opposed to proliferation

Subcellular Location

Cell membrane; Secreted

Tissue Specificity

Expressed in trachea, duodenum and intestine. Lower expression in stomach, salivary glands, liver, gallbladder, and kidney

Subunit

A heterodimeric complex, composed of a mucin-4 alpha chain and a cysteine-rich transmembrane mucin-4 beta chain. Mucin-4 beta chain interacts with ERBB2 via the EGF-like domain 1. In nonpolarized cells, associates with ERBB2 and ERBB3

• Desseyn J.-L. et al. Cloning, chromosomal localization and characterization of the murine mucin gene orthologous to human MUC4. — Eur. J. Biochem. (2002)
• Church D.M. et al. Lineage-specific biology revealed by a finished genome assembly of the mouse. — PLoS Biol. (2009)
• Bartman A.E. et al. Identification and structure of a mouse homolog to the human MUC4 gene. (DEC-)
• The status, quality, and expansion of the NIH full-length cDNA project: the Mammalian Gene Collection (MGC). — Genome Res. (2004)
• Lee C.G. et al. Transgenic overexpression of interleukin (IL)-10 in the lung causes mucus metaplasia, tissue inflammation, and airway remodeling via IL-13-dependent and -independent pathways. — J. Biol. Chem. (2002)
• DeSouza M.M. et al. Cloning and expression analysis of mouse ascites sialoglycoprotein-2 (ASGP-2)/Mucin 4 (Muc4). (JUN-)